The invention relates to pluggable optical communications modules. More particularly, the invention relates to a pluggable optical communications module having an improved latching/delatching mechanism.
One type of optical fiber cable is terminated on one or both ends with a pluggable optical communications module. The optical communications module is an optical receiver module, an optical transmitter module or an optical transceiver module. The connector module has a module housing that houses the electrical, optoelectronic and optical components of the module. Although various pluggable module designs exist, the module housing is typically configured to be plugged into an opening formed in a cage. Module housings of this type typically include a pair of cage latch stops formed on opposite outer side walls of the module housing that engage a pair of cage latches formed on opposite side walls of the cage to secure the module housing to the cage when the module housing is fully inserted into the cage. The pair of slider arms is part of a latching/delatching mechanism of the module housing. The latching/delatching mechanism also includes a bail that is rotatable by a user to allow it to be moved from a latched position into a delatching position. The bail is mechanically coupled to a yoke that is integrally formed with a pair of slider arms of the latching/delatching mechanism. The slider arms extend along opposite outer side walls of the module housing. The distal ends of the slider arms have respective hook features formed thereon that curve outwardly away from the respective outer side walls of the module housing.
When the module housing is fully inserted into the cage, the slider arms are positioned in between the respective outer side walls of the module housing and the respective inner side walls of the cage. Rotation of the bail into the delatching position pulls the slider arms along the respective outer side walls of the module housing in the direction toward the cage opening. As the slider arms move in this direction, the hook features on the distal ends of the arms press outwardly against the respective cage latches formed on the inner side walls of the cage, thereby causing the cage latches to disengage the respective cage latch stops formed in the opposite outer side walls of the module housing. The user then uses the bail as a handle to pull the module from the cage.
One of the disadvantages of the current latching/delatching mechanisms of the type described above relates to the manner in which the bail is secured to the module housing. Typically, opposite ends of the bail are secured to the module housing by press-fitted pins that are pressed through respective openings formed in the bail such that the ends of the bail are sandwiched in between the heads of the press-fitted pins and the outer side walls of the module housing. With this type of arrangement, forces exerted on the bail are transferred to the pins, and excessive forces can cause the pins to loosen, which can ultimately cause the latching/delatching mechanism to fail. Another disadvantage of latching/delatching mechanisms of this type is that the application of excessive force to the bail when attempting to extract the module from the cage can result in the latching/delatching mechanism becoming dislodged from the module housing.
Yet another disadvantage of latching/delatching mechanisms of this type is that the slider arms can cause the electromagnetic interference (EMI) gasket disposed about the cage opening to peel. The cage opening typically has an EMI gasket formed in or secured to the inner and outer top, bottom and side walls of the cage opening. The slider arms come into contact with the inner EMI gasket as the module housing is inserted into and retracted from the cage. This contact can cause the EMI gasket to peel, which can degrade the integrity of the gasket and result in improper EMI leakage from the cage.
Accordingly, a need exists for an optical communications module that has an improved latching/delatching mechanism that overcomes the above-described disadvantages.
The invention is directed to a pluggable optical communications module and to an optical communications assembly that incorporates the module. The pluggable optical communications module comprises a module housing and a latching/delatching mechanism secured to the module housing. The module housing has a receptacle formed therein for receiving an end of an optical fiber cable. The module housing has at least a top, a bottom, a first side and a second side. The top and bottom are interconnected by the first and second sides such that the top, the bottom, the first side, and the second side form an encasement. Components of the module are housed in the encasement. The first and second sides have first and second cage latch stops thereon, respectively. The latching/delatching mechanism includes at least a bail and a slider. The bail is pivotally coupled with the module housing to allow the bail to rotate between a latched position and a delatched position.
The slider includes at least first and second slider arms and a yoke, which is joined with proximal ends of the first and second slider arms and is positioned to mechanically couple with the bail as the bail is pivoted from the latched position to the delatched position. The first slider arm extends along at least a portion of the first side of the module housing and is partially encased within the encasement. At least a distal end of the first slider arm is outside of the encasement. The second slider arm extends along at least a portion of the second side of the module housing and is partially encased within the encasement. At least a distal end of the second slider arm is outside of the encasement. The distal ends of the first and second slider arms include first and second hook features, respectively, that curve outwardly relative to the first and second sides, respectively, of the module housing.
In accordance with one embodiment, the first and second slider arms are partially encased by disposing them in first and second channel grooves, respectively, of the module housing. The first side of the module housing has a first inner side wall and a first outer side wall that are separated by a small gap to form the first channel groove. The second side of the module housing has a second inner side wall and a second outer side wall that are separated by a gap to form the second channel groove.
The optical communications assembly comprises a cage and an optical communications module disposed in an opening of the cage. The cage has a top, a bottom, a first side and a second side. The top and bottom of the cage are interconnected by the first and second sides of the cage such that the top, the bottom, the first side, and the second side of the cage define the cage opening. First and second cage latches are disposed on the first and second sides of the cage, respectively, within the opening. The pluggable optical communications module comprises a module housing and a latching/delatching mechanism secured to the module housing. The latching/delatching mechanism includes at least a bail and a slider. The bail is pivotally coupled with the module housing to allow the bail to rotate between a latched position and a delatched position. The slider includes at least first and second slider arms and a yoke. The yoke is joined with proximal ends of the first and second slider arms and is positioned to mechanically couple with the bail as the bail is pivoted from the latched position to the delatched position. The first slider arm extends along at least a portion of the first side of the module housing and is partially encased within the encasement. At least a distal end of the first slider arm is outside of the encasement. The second slider arm extends along at least a portion of the second side of the module housing and is partially encased within the encasement. At least a distal end of the second slider arm is outside of the encasement. The distal ends of the first and second slider arms include first and second hook features, respectively, that curve outwardly relative to the first and second sides, respectively, of the module housing.
These and other features and advantages of the invention will become apparent from the following description, drawings and claims.
The invention is directed to an optical communications module having a latching/delatching mechanism that overcomes the foregoing disadvantages and that provides further advantages. The aforementioned problem of the slider arms coming into contact with the EMI gasket of the cage and potentially damaging the gasket is prevented by partially encasing the slider arms inside of the module housing. In this way, the slider arms do not come into contact with the cage as the module housing is being inserted into and extracted from the cage. The distal portions of the slider arms on which the hook features are formed remain outside of the module housing to allow them to come into contact with the cage latches during delatching. Additionally, partially encasing the slider arms in the module housing provides the latching/delatching mechanism with greater rigidity and eliminates the possibility of the latching/delatching mechanism becoming dislodged in the event that excessive force is applied to the bail when attempting to extract the module from the cage. Illustrative, or exemplary, embodiments will now be described with reference to
An illustrative embodiment will now be described with reference to
With reference to
With reference to
The dowel pins 5a and 5b and the configuration by which they are held in place in the housing 3 provide a much more robust solution than the press-fitted pins of the known arrangement. By using the dowel pins 5a and 5b instead of press-fitted pins for this purpose, excessive forces that are exerted on the dowel pins 5a and 5b will be transferred to the housing 3, which makes it less likely that the bail 2 and the slider 4 will be dislodged from the module housing 3. In addition, the new arrangement makes it virtually impossible for the pins 5a and 5b to come loose in the event that excessive forces are applied to the bail 2 during the extraction process. The bail 2 pivots or rotates about the pins 5a and 5b between the latched position shown in
With reference to
There are multiple advantages to encasing all but the distal ends 4a′ and 4b′ of the slider arms 4a and 4b within the housing 3. One of the advantages is that it increases the rigidity of the slider 4 compared to known solutions where the slider arms are exposed along the outer side surfaces of the module housing. The increased rigidity prevents the latching/delatching mechanism from being dislodged from the module housing 3 and protects the latching/delatching mechanism from being damaged by external factors, thereby improving reliability and longevity. Another advantage of encasing most of the slider arms 4a and 4b within the housing 3 is that it prevents the slider arms 4a and 4b from coming into contact with the EMI shield 40 of the cage 20 when the module 1 is inserted into and retracted from the cage 20, as will be described below in more detail with reference to
There is also an advantage to forming the cage latch stops 8 in the upper housing portion 3a. In known pluggable modules of the type described above, typically one cage latch stop is formed on the upper housing portion and the other cage latch stop is formed on the lower housing portion. Because of manufacturing tolerances, the upper and lower housing portions may not be precisely aligned at their interface when they are assembled, which can result in the cage latch stops on the upper and lower housing portions not being precisely aligned. This, in turn, can result in the module not latching properly within the cage, which can lead to other problems. Because both cage latch stops 8 are formed in the upper housing portion 3a, precise alignment of the cage latch stops 8 with one another is ensured. The upper and lower housing portions 3a and 3b are typically made by die casting zinc, and therefore can be made to meet very tight tolerances. The housing portions 3a and 3b, however, could be made of other materials and by other processes, as will be understood by those of skill in the art in view of the description being provided herein. The bail 2 and the slider 4 are typically made of a metallic material such as sheet metal or stainless steel, for example.
With reference to
The cage 20 has an EMI gasket 40 on the inner and outer surfaces of the cage opening. Such EMI gaskets are commonly used in cages that are adapted to mate with pluggable optical communications modules. As indicated above, the known latching/delatching mechanisms come into contact with the portions of the EMI gasket that are disposed in the inner surfaces of the cage opening and can cause them to peel or otherwise become damaged. Because all but the distal ends 4a′ and 4b′ of the slider arms 4a and 4b are encased within the housing 3, the slider 4 does not come into contact with the EMI gasket 40 when the module 1 is inserted into and extracted from the cage 20. This is an additional benefit that is realized by encasing all or most of the slider 4 within the housing 3. Although the distal ends 4a′ and 4b′ of the slider arms 4a and 4b are outside of the housing 3, they are within a recess of the upper housing portion 3a and therefore only make contact with the respective cage latches 21, which project inwardly from the respective side walls of the cage 20.
With reference again to
It should be noted that the invention has been described with reference to illustrative embodiments and that the invention is not limited to these embodiments. Those skilled in the art will understand the manner in which modifications can be made to the illustrative embodiments and that all such modifications are within the scope of the invention. For example, although the module housing 3 and the slider 4 have been described as having particular configurations, persons skilled in the art will understand the manner in which these configurations may be modified while still achieving the goals of the invention. For example, while the upper housing portion 3a has been described as having outer side walls 15a/16a and inner side walls 15b/16b in order to form the channel grooves 14a and 14b, the slider arms 4a and 4b could be encased within the module housing 3 in other ways. These and other modifications may be made to the embodiments described herein and all such modified embodiments are also within the scope of the invention, as will be understood by persons skilled in the art.